body{background-color:pink;position:relative;margin:0;padding:0;font-family:"Helvetica Neue",Helvetica,sans-serif;font-size:30px}.box{display:flex;flex-wrap:wrap}.box div{width:100px;height:100px;border:2px solid red;cursor:pointer;transition:all .25s}.box div.elf{background-color:#ff0}.box div.neunzehn{background-color:#add8e6}.box div:hover{background-color:red}